1. Field
Exemplary aspects of the present disclosure relate to a camera module.
2. Background
A camera module can perform an auto focusing function by arranging a lens barrel mounted with a plurality of lenses at an upper surface of a PCB (Printed Circuit Board) installed with an image sensor and by moving the lens barrel or at least one sheet of lens relative to the image sensor. The auto focusing function may be implemented by various actuators, where an auto focusing method using a VCM (Voice Coil Motor) is generally employed.
In the VCM, a magnet is mounted at a holder member, which is fixedly mounted at an upper surface of the PCB. A bobbin is vertically and reciprocatingly arranged at a position opposite to that of the magnet, where the bobbin is wound with a coil at a periphery. The bobbin is mounted at an inner surface with a lens barrel having a plurality of lenses. The coil is electrically connected to the PCB, and to this end, a terminal of conductive material is soldered to a metal-materialed elastic member to elastically support the bobbin.
When the terminal is soldered to a bottom elastic member as noted above, the terminal and the bottom spring are applied to a structure formed with mutually different members, where a soldered position corresponds to a contact surface between an upper surface of the bottom spring and a terminal boss of terminal so formed as to contact the bottom spring.
The contact surface between the terminal and the bottom spring is so formed as to allow a maximum electrical connection. However, there disadvantageously occurs a problem of solder overflow depending on workmanship, because the soldering process is manually done. Particularly, due to miniaturization of mobile devices, the size of camera module is decreased to result in generation of frequent soldering defects, from which bad assembly or erroneous operation is caused.
Furthermore, an empty space is generated as large as thickness of the bottom elastic member, through which foreign objects may be introduced into a camera module.
Meanwhile, the bobbin performs an auto focusing function while reciprocating in parallel with an axial direction. At this time, the bobbin reciprocates in repetitive contact with a base, whereby the bobbin or the base may be damaged through the repetitive contact. In order to avoid this problem, a plurality of bosses is separately formed at a surface opposite to the base of the bobbin to allow a floor surface of the boss to surface-contact the base.
Furthermore, the base is mounted with an IR (Infrared) cut-off filter at a position opposite to the image sensor, where the bobbin frequently contacts the base at a position near to a contact surface of the IR cut-off filter. Thus, there is a need to reduce the size of the boss, so that interference with the IR cut-off filter can be prevented. As a result, the boss may be frequently damaged by repetitive use or external shock.
When the boss is damaged, foreign objects generated therefrom can pollute the IR cut-off filter arranged at a position near to the boss, and when the IR cut-off filter is polluted by the foreign objects, a pale round image or a black spot is generated on the image of the camera module, resulting in generation of bad camera module.